81 lines
2.9 KiB
JavaScript
81 lines
2.9 KiB
JavaScript
'use strict';
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// https://github.com/tc39/proposal-iterator-helpers
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var $ = require('../internals/export');
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var call = require('../internals/function-call');
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var aCallable = require('../internals/a-callable');
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var anObject = require('../internals/an-object');
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var getIteratorDirect = require('../internals/get-iterator-direct');
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var createAsyncIteratorProxy = require('../internals/async-iterator-create-proxy');
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var createIterResultObject = require('../internals/create-iter-result-object');
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var getAsyncIterator = require('../internals/get-async-iterator');
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var closeAsyncIteration = require('../internals/async-iterator-close');
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var AsyncIteratorProxy = createAsyncIteratorProxy(function (Promise) {
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var state = this;
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var iterator = state.iterator;
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var mapper = state.mapper;
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var innerIterator;
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return new Promise(function (resolve, reject) {
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var doneAndReject = function (error) {
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state.done = true;
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reject(error);
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};
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var ifAbruptCloseAsyncIterator = function (error) {
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closeAsyncIteration(iterator, doneAndReject, error, doneAndReject);
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};
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var outerLoop = function () {
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try {
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Promise.resolve(anObject(call(state.next, iterator))).then(function (step) {
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try {
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if (anObject(step).done) {
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state.done = true;
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resolve(createIterResultObject(undefined, true));
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} else {
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var value = step.value;
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try {
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Promise.resolve(mapper(value)).then(function (mapped) {
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try {
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state.innerIterator = innerIterator = getAsyncIterator(mapped);
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state.innerNext = aCallable(innerIterator.next);
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innerLoop();
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} catch (error4) { ifAbruptCloseAsyncIterator(error4); }
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}, ifAbruptCloseAsyncIterator);
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} catch (error3) { ifAbruptCloseAsyncIterator(error3); }
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}
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} catch (error2) { doneAndReject(error2); }
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}, doneAndReject);
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} catch (error) { doneAndReject(error); }
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};
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var innerLoop = function () {
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if (innerIterator = state.innerIterator) {
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try {
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Promise.resolve(anObject(call(state.innerNext, innerIterator))).then(function (result) {
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try {
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if (anObject(result).done) {
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state.innerIterator = state.innerNext = null;
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outerLoop();
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} else resolve(createIterResultObject(result.value, false));
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} catch (error1) { ifAbruptCloseAsyncIterator(error1); }
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}, ifAbruptCloseAsyncIterator);
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} catch (error) { ifAbruptCloseAsyncIterator(error); }
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} else outerLoop();
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};
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innerLoop();
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});
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});
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$({ target: 'AsyncIterator', proto: true, real: true, forced: true }, {
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flatMap: function flatMap(mapper) {
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return new AsyncIteratorProxy(getIteratorDirect(this), {
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mapper: aCallable(mapper),
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innerIterator: null,
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innerNext: null
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});
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}
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});
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